Your girlfriend found out that you've been cheating on her. Hope you enjoyed yourself because that will be the last time that ever happens. She is a veterinarian and has you in her clinic, tied down and helpless. Just so you remember that the last person to make you orgasm was her, she gives you a handjob while telling you all about what's going to happen. She's going to cut off your balls. Don't be so shocked! She's done this hundreds of times--there really isn't much of a difference between your testicles and the ones she castrates regularly. It's going to hurt, but you hurt her by fucking around, so just take the punishment you deserve. After removing your testicles, she is so excited by the power she has that she can't help but make herself orgasm right in front of you. Such a shame you'll never be able to enjoy her pussy again.